hey guys and gals, im at my wits end,

2009 chevy suburban 1500, replaced 2 calipers and all the pads. I only had the brake line off the RH front for 2 minutes to re/re caliper, now the pedal sinks to the floor.

Ive done ABS bleed function 15+ times, manual bleed, press ure bleed etc. Engine off, the pedal pumps up and feels nice. Engine on, pedal sinks to the floor like a rock.

Went ahead and shotgun troubleshoot and replaced master cylinder, did a bench bleed and install. Still pedal sinks to the floor engine off.

The ABS modulator bleed sounds loud and firm, ive run with a battery charger to make sure no voltage drop.

I cant get any air "out" anywhere, all i get is clean and consistant fluid out of all 4 corners. Any help?

thanks and happy hunting

 

Are you using a scan tool with automated bleed function or just turning on the ABS pump. I think there is a difference between the two.

 

Snap on scanner doing automated bleed. With battery charger on

 

I've ran into this a few times. Try bleeding air out of the lines that run from the master cylinder to the ABS pump. Sometimes you need to bleed those lines at both ends. What sometimes happens is when you push the pedal the air won't make it all the way to the pump and start to rise back up towards the master cylinder and the air never makes it out either end. Try bleeding those lines, doing the automated bleed, then bleed brakes as usual. Let me know if you still have problems